Devices, apparatuses, and articles of manufacture consistent with the present disclosure relate to a semiconductor memory device, and more particularly, relate to a semiconductor memory device which has an input/output function implemented by a separate chip.
Mobile devices such as a smart phone, a tablet PC, a digital camera, an MP3 player, a PDA, and the like may be used widely. Such mobile devices may have a dynamic random access memory (DRAM) or a nonvolatile memory device. The integration of memory devices may increase according to a need for a high density, particularly in mobile devices.
However, it is technically difficult to apply the same design rule to all components of a semiconductor memory. In addition, a stack-type multi-chip technique for stacking memory devices tends to improve the integration. A wiring rearranging process, for example, may be used to stack the same types of memory devices and to electrically connect the stacked memory devices with an external device. However, such a wiring rearranging process may increase a cost and lower the reliability of a memory device.
Accordingly, although a design rule may be applied to increase integration, a yield may be decreased. That is, there may be a trade-off between the design rule and the yield.